US2851727A - Granular plastic lining machine - Google Patents

Description

Sept. 16, 1958 E. A. WILCKENS ET AL GRANULAR PLASTIC LINING MACHINE Filed Aug. 11, 1955 16 Sheets-Sheet 1 xii INVENTORS:

ATTORNEYS.

Sept. 16, 1958 E. A. WILCKENS, EIAL 2,851,727

GRANULAR PLASTIC LINING MACHINE Flled Aug 11 1955 16 Sheets-Sheet 2 INVENTORS:

Ejhe A Wc'lckem,

owwm @mm m .m m mm amw m? mw Sept. 16, 1958 E. A. WILCKENS ETAL 2,851,727

GRANULAR PLASTIC LINING MACHINE Filed Aug. 11, 1955 Sept. 16,1958 I E. A. WlLCKENS ETAL GRANULAR PLASTIC LINING MACHINE l6 Sheets-Sheet 5 Ejbp AMa lckens, Altl Liam CRaisner, MRedc'li ATTORNEYS.

Filed Aug. 11, 1955 GRANULAR PLASTIC LINING MACHINE Filed Aug. 11, 1955 16 Sheets-Sheet 6 E1 A.Wilbkqns, 0.12m, y v EflwpndMReddiqg, 2.90 BY ATTORNEYS.

Sept 18, 195 E. A. WILCKENS ET AL 2,3 72? GRANULAR PLASTIC LINING MACHINE l6 Sheets-Sheet 9 Filed Aug. 11, 1955 INVENTORSK Ejzb e A .Afilckem mlliam GRainer, zm 'f w V Y ATTORNEYS.

Sept. 1%, 1958 E. A. WILCKENS ET AL GRANULAR PLASTIC LINING MACHINE 16 Sheets-Sheet 10 Filed Aug. ll, 1955 Nam 16 Sheets-Sheet 12 G/XJW INVENTORE' E.- A. WILCKENS 7 ET AL GRANULAR PLASTIC LINING MACHINE Sept. 16, 1958 Filed Aug. 11, 1955 a? sr n 2m hum! u in M m ww g EWE Sept. 16, 1958 E. A. WILCKENS ETAL GRANULAR PLASTIC LINING MACHINE INVENTORS. ,Njilckenm/ 16 Sheets-Sheet l3 Vvfilliam C. Rainer,

Filed Aug. 11, 1955 BY EduJpr d MReddin ATTORNEYS Sept. 16, 1958 E. A WILCKENS ETAL GRANULAR- PLASTIC LINING MACHINE Filed Aug. 11, 1955 16 Sheets-Sheet l4 INVENTORS: Ejfip A.Wilckens,

ATTORNEYAS.

. iner, ,dzupzr dM. Redd Sept. 16, 1958 Filed Aug. 11, 1955 E. A. WILCKENS ET AL GRANULAR PLASTIC LINING MACHINE 16 Sheets-Sheet l5 ATTORNEYS.

Wp Z xKAW Sept. 16, 1958' E. A. WILCKENS ETAL GRANULAR PLASTIC LINING MACHINE 16 Sheets-Sheet 16 Filed Aug. 1]., 1955 IN VENTORS "2/ tn W ATTORNEYS.

Ejzlye Am rackem; William (lRainer, BY Eflwpu cl MRedd 2,851,727 I GRANULAR PLASTIC LlNlNG MACHINE Elbe A. Wilckens', William C. Rainer, and Edward M.

Redding, Baltimore, Md., assignors to Crown Cork & Seal Company, Inc., Baltimore, Md., a corporation of New York Application August 11, 1955, Serial No. 527,710 14 Claims. (Cl. 18-20) This invention relates to the art of lining closures and more particularly to an improved machine for lining closures, such as bottle crowns and caps, with a granular or powdered moldable sealing material, preferably of plastic.

One object of the present invention is to provide a machine for lining a closure with a cushion liner of a granular moldable sealing material which is continuous in its operation thereby obtaining optimum output.

A further object of the present invention is the provision of an improved plastic sealing material charge supplying mechanism with which the traveling support means for the closures cooperates to deposit a measured charge of sealing material into the central interior of closures so as to soften the same in the central interior 7 of the closures, and to hot mold the preheated charges in the closures to a desired shape.

These and other objects of the present invention will become more apparent during the course of the following detailed description and appended claims.

The invention may best be understood with reference to the accompanying drawings wherein illustrative embodiments are shown.

In the drawings:

Figure 1 is a somewhat schematic top plan view illustrating one form of a machine embodying the principles of the present invention; j

Figure 2 is a fragmentary front elevational view of the machine shown in Figure 1;

Figure 3 is a somewhat schematic horizontal sectional view showing the drive mechanism of the machine;

Figure 4 is a fragmentary top plan view of the shell delivery wheel and feeding dial of the machine illustrating the manner in which the empty shells are transferred onto the combined lining and molding dial mechanism;

Figure 5 is a fragmentary side elevational view partly in section of the charge supplying mechanism showing the same in cooperating relationship with the combined lining and molding dial mechanism, the latter being in vertical cross-section for clear illustration;

Figure 6 is an enlarged, fragmentary top plan view showing a latch member of the combined lining and molding dial mechanism;

Figure 7 is a cross-sectional view taken along the line 7-7 of Figure 5;

Figure 8 is a cross-sectional view taken along the line 8.-8 of Figure 5; 1 e

c 2,851,727 Ice Patented Sept. 16, 1958 Figure 9 is a cross-sectional view taken along the line.

9-9 of Figure 5 showing the parts in their normal operating position;

I Figure 10 isan enlarged, fragmentary horizontal sectional view showing an upper gate valve of the charge supplying mechanism;

Figure 11 is an enlarged top plan view of an upper gate valve part of the charge supplying mechanism;

Figure 12 is a view similar to Figure 10 showing a lower gate valve of the charge supplying mechanism;

Figure 13 is a fragmentary view similar to Figure 9 showing the parts in their inoperative no-charge position;

Figure 14 is a fragmentary vertical sectional view showing a plunger device of the combined lining and 'molding dial mechanism in its initial pressure applying position; a

Figure 15 is a view similar to Figure 14 showing the plunger device in its final molding pressure applying position;

Figure 16 is a front elevational view of the charge supplying mechanism with parts in vertical section;

Figure 17 is a side elevational view of the shell delivery wheel and feeding dial;

Figure 18 is a front elevational view of the shell delivery wheel and feeding dial;

Figures 1922 are a series of fragmentary vertical sectional views showing the manner in which the slide members of the combined lining and molding dial mechanismoperate to move the shells onto their seats;

Figure 23 is a view similar to Figure 1 showing a modified embodiment of the machine;

Figure 24 is a view similar to Figure 5 illustrating the modified machine;

Figure 25 is a front elevational view of the charge supplying mechanism;

Figure 26 is an enlarged, fragmentary vertical sectional view showing the fluid pressure applying means of the modified machine with the parts in their exhaust position;

Figure 27 is a view similar to Figure 26 showing the parts in their pressure applying position;

Figure 28 is a view similar to Figure 1 showing a further modification of a machine embodying the principles of the present invention;

Figure 29 is a top plan view showing the charge supplying mechanism of the machine of Figure 28 in c0- operative relation to the preheating and lining dial;

Figure 30 is a horizontal sectional view of the structure 1 shown in Figure 29 with the parts in their inoperative nocharge position;

Figure 31 is a view of the structure shown in Figure 29 similar to Figure 5;

Figure 32 is a front elevational view of the charge supplying mechanism of the machine of Figure 28;

Figure 33 is a vertical sectional view of the molding dial mechanism of the machine of Figure 28; and

Figure 34 is a fragmentary top plan view of the molding dial mechanism partly broken away.

General construction and operation The machines illustrated in the drawings as embodying the principles of the present invention are intended to be used for applying liners of a granular or powdered plastic material to the interior of closures of the crown type. As shown in the drawings, a crown type bottle cap comprises a metal shell S having an annular fluted skirt and a liner L applied to the central interior thereof;

Referring now to the embodiment of the invention disclosed in Figures 1-22, shells S are delivered to the machine from a suitable source (not shown) from where they are directed into a shell feeding mechanism 50, as shown in Figure 2. The shells move downwardly from feeding mechanism 50 in single file by way of a chute 52. Chute 52 includes a rectifier 54 and delivers properly facing shells to a.shell delivery Wheel 56. The shell feed.- ing mechanism 50, chute 52, and rectifier 54 (shown in phantom lines) are constructed and operate in the manner disclosed inPatent No. 2,703,130, issued March 1, 1955, to Eibe A. Wilckens and Harvey A. Rau and form no part of the present invention. The shell delivery wheel 56 transfers the properly facing shells onto a shell feeding dial 58 as shown in Figures 4, 17 and 18, from where they are transferred onto a combined lining and molding. dial mechanism 60.

On the lining and molding dial mechanism 60, the shells are moved into a first radial position wherein a measured charge of granular plastic molding material is deposited into the shells-by a charge supply mechanism 62. The charge supplying mechanism 62 includes a noshell no-charge mechanism 63 operable to prevent the deposit of a charge when no shell is presented to receive the charge. The charged shells are then moved into a second radial position where they are moved past a heating means 64 so as to soften the plastic charges. In addition, while the heated charged shells are in the second radial position, a suitable molding pressure is applied. This pressure is preferably applied in two stages; first, an initial pressure which acts to more or less insure that the softened charges will be distributed evenly within the shells, and second, a final higher molding pressure to shape the liners. The reason for the two stage application of pressure is that if a high final molding pressure is applied too soon to the charges, the latter tend to blister resulting in imperfectly formed liners. It has been found that the final molding pressure need not be applied for a longer period than two or three seconds and the initial pressure is applied mainly to insure that as the granular plastic softens, it will assume an evenly distributed shape within the shell, as noted above.

After the final molding-pressure has been applied to the charges within the shells, the finished molded closures are then transferred from the lining and molding dial mechanism 60 onto a chute 66 which directs them ontoa transverse conveyor belt 68. From the conveyor 68, the finished closures are transferred, as by a paddle wheel (not shown) onto a main inspection conveyor 70.

As shown in Figures 1-3, the various dials and mechanisms noted above may be suitably mounted on a main frame or table 72 which houses a suitable drive mechanism 74 for imparting rotation to the various dials and mechanisms.

The lining and molding dial mechanism 66 noted above is intended to apply the two stage pressure by means of spring energy suitably controlled in a manner hereinafter to be more fully described. in Figures 23-27, there is shown a similar machine embodying a modified means for applying two stage pressure wherein the initial pressure is applied byspring energy and the final molding pressure is applied by fluid energy.

In Figures 28-34, there is shown a modified form of machine embodying the principles of the present invention which includes the shell feeding mechanism 50, chute 52, rectifier 54', shell feeding wheel 56, and shell feeding dial 58 noted above in regard to the embodiment of Figures 1 through 22. The empty shells on the shell feeding dial 58 are transferred onto a preheating and lining dial 76 which carriesthe empty shells past a charge.

supplying mechanism, similar to the charge supplying mechanism 62 but suitably modified to accommodate the different machine. After the shells have received a charge from the modified charge supplying mechanism 62, they are moved past a heating means 80 which. is

operable to soften the charges within the shells. The preheated charged shells are then transfererd from the preheating and lining dial 76 onto a molding dial mechanism 82 where they are subjected to further heat, as by heating means 84, and a final molding pressure is applied to form finish molded liners. The finished closures are transferred from the molding dial mechanism 82 onto a chute86 which directs them onto a transverse endless conveyor 88. A paddle wheel (not shown) transfers theclosures from the conveyor 83 onto a main inspection conveyor 90.

The various dials and mechanisms of the machine of Figures 28-34 may be suitably mounted above a main frame-or table 92 and provided with a drive mechanism similar to the drive mechanism 74 previously described but suitably modified to impart rotary motion to the different dials and mechanisms of the different machine. The detailed construction and operation of each of the dials and mechanisms of all of the embodiments noted above are hereinafter described in detail.

Drive mechanism As shown in Figure 3, the drive mechanism 7 comprises a main drive shaft ltltlsuitably journalled in the main frame 72 for rotation about a horizontal axis. The drive shaft may be driven from any suitable source of power (not shown). A worm gear 102 is fixedly mounted on the central portion of the drive shaft by any suitable means and is arranged to mesh with a gear 104 fixed to a vertical shaft 106. Shaft 106 is journalled in the main frame 72 by a bearing 168 and the upper end thereof carries the combined lining and molding dial mechanism: 60. The charge supplying mechanism 62 is driven by a shaft 110 journalled in the frame 72, as by bearing 112. The shaft 110 is drivingly connected with the shaft 106 through a suitable gear train which includes a large pinion gear 114 affixed to the combined lining and molding dial mechanism shaft 106, a gear 116 affixed to the shaft 110 and a pair of intermediate idler gears 118 suitably journalled in the frame so as to mesh with each other and the respective gears 114 and 116. The Wilckens and Rau: shell feeding mechanism 50 may be driven from a vertically extending shaft 120 drivingly connected with the gear 116 by means of a suitable gear train including a spur gear 122 fixedly mounted on the shaft 120 and idler gears 124 and 126. The idler gears 124 and 120 may be suitably journalled within the frame 72 for rotation about a common vertical axis, the gear 124 being of a smaller size and meshing with the gear 122 while the gear 126 is of a larger size and meshes with gear 116.

The shell feeding dial 58 is driven by a shaft 128 journalled in the frame 72, as by bearing 130, and is drivingly connected with the large pinion gear 114 of shaft 110 through a suitable gear train including a spur gear 132 fixedly mounted on the shaft 128 by any suitable means and a pair of intermediate idler gears 134. The idler gears 134 may be journalled within the frame by any suitable means so as to mesh with each other and with the respective gears 114 and 132.

Shell delivery wheel and feeding dial The shell feeding dial 58, as more particularly shown in Figures 4, 17, and 18, includes a circular dial plate fixedly mounted on the upper end of shaft 123. The plate 140 is provided with a plurality of circumferentially spaced pockets or seats 142 within which the empty shells are adapted to be positioned. Secured to the shaft 12:"; above plate 140 is a bevel gear 144 arranged to mesh with a cooperating bevel gear 146 journalled on one end of ashaft 148, the other end of which is fixedly mounted above the table by a suitable support 150. The shell delivery wheel56 comprises a wheel plate 152 fixedly connected with gear 146 for rotation therewith about shaft 148. Fixedly'mounted on the plate 152 are a plurality of radially extending fingers or pads 154- disposed in circumferentially spaced relation around the entire periphery thereof. As shown in Figure 18, these pads are preferably made inte ral with the plate 152 and are operable to enter within the interior of the properly facing empty shells issuing from the chute 52 so as to transfer them from the lower end of the chute into the pockets 142 of the dial plate 140.

A segmental guard rail member 156 is fixedly mounted by any suitable means on the table 72 in surrounding relation to the portion of the outer periphery of the dial plate extending between the shell delivery wheel 56 and the lining and molding dial mechanism 60. The member 156 is preferably L-shaped in cross-section and includes a horizontally disposed leg 158 spaced above the dial plate pockets sumciently to permit free passage of the shells therebel'ow and a vertically disposed leg 160 spaced outwardly of the dial plate pockets sufiiciently to prevent radial movement of the shells during their movement with the dial. The end of the horizontal leg 158 adjacent the shell delivery wheel 56 is provided with a cut out portion 162 through which the wheel plate 152 extends. The cut out end of horizontal leg 158 is thus positioned so as to engage the upper edge of the shells carried by the pads 154 and serves to insure that the shells are stripped from the pads. A horizontal plate 164 is fixedly mounted by any suitable means on the table 72 just below the dial plate pockets adjacent wheel plate 152 to support the shells as they are stripped or freed from the pads so as to insure that they will be correctly positioned in the dial plate pockets.

The shells are moved by the dial plate pockets along plate 164 until the end thereof is reached after which the pockets serve as their sole support. A second horizontal plate 166 is fixedly mounted by any suitable means on the table 72 just below the dial plate pockets adjacent the lining and molding dial mechanism 60 to support the shells as they are transferred thereto.

Combined lining and molding dial mechanism As best shown in Figure 5, the combined lining and molding dial mechanism 60 comprises a main dial frame 180 fixedly secured by any suitable means to the shaft 106 above the table 72. Secured in vertically spaced relation to the lower outer periphery of the dial frame 180 by any suitable means, such as by bolts 182, is a lower annular ring 184 having a plurality of circumferentially spaced outer pockets or seats 186 formed in the upper surface thereof and a corresponding plurality of circumferentially spaced inner pockets or seats 188. These seats 186 and 188 serve to support the shells during their movement on the combined lining and molding dial mechanism 60 as will be more fully explained hereinafter. An upper annular ring 190 is interposed between the lower surface of the dial frame 180 and the upper surface of the lower ring 184 and may be secured in position by means of the bolts 182 previously described. The lower surface of the ring 190 is provided with a plurality of radially extending grooves 192, a groove being disposed above each seat, for slidably receiving a plurality of radially disposed slide members 194.

As shown in Figures 4, and 19-22, each slide member 194 is provided with a magnet 196 which is disposed on the outer end thereof and arranged to contact the shells S. The rearward end of each slide member 194 has a depending vertical stub shaft 198 secured thereto by any suitable means, such as Welding or the like. Each of the stub shafts 198 has journaled thereon a cam roller 200 which is secured below the associated slide member 194 by any suitable means, such as nut 202. Cam rollers 200 are arranged to cooperate with a cam track 204 which serves to move the slide members radially, as will hereinafter more fully appear. The cam track 204 comprises a circular supporting frame 206 having a pair of concentric upstanding rings 208 and 210. The rollers 200 extend within a cam groove 212 formed by a pair of circu- 6 lar ring members 214 and 216 rigidly mounted on the rings 208 and 210, respectively and extending inwardly therefrom.

Referring now more particularly to Figure 4, it will be seen that the cam track 204 positions the cam rollers 200 and hence, the slide members 194 so that the magnets 196 on the outer ends thereof will be in an extreme outer position to thereby engage the empty shells issuing from the shell feeding dial 58. The magnets engage the empty shells and as the slide member is moving radially inwardly, the shells are moved by the magnets onto the outer seats 186 of the dial. The shells are maintained on seats 186 during their movement with the dial frame 180 past the charge supplying mechanism 62, which is arranged to supply a measured charge of granular plastic material into each shell as it moves thereby. In order to guide the granular plastic material into the shells, a lower annular flange 218 (see Figure 5) is formed on the dial frame 180 at the lower peripheral end thereof. A series of circumferentially spaced funnel shaped apertures 220 extend through the outer end of the annular flange 218, an aperture 220 being disposed above each of the seats so as to funnel the granular material into the central interior of the shells. If desired, concentric apertures 222 may be formed in the lower annular ring 184.

After the charges have been deposited into the shells, cam track 204 operates cam rollers 200 to move the slide members 194 radially inwardly so that the magnets 196 thereof will move the associated shells from the seats 186 onto the adjacent seats 188 preparatory to the molding operation, see Figures 19-22.

In order to apply a suitable molding pressure to the charges within the shells, a plunger device 224 is mounted on the outer periphery of the dial frame 180 above each of the seats 188. Consequently, the outer periphery of the dial frame 180 is provided with an intermediate annular flange 226 spaced above the flange 218 and an upper annular flange 228 spaced above the flange 226. Flanges 218, 226 and 228 are provided with a series of circumferentially spaced, concentric apertures 230, 232 and 234, respectively, within which the plunger devices 224 are mounted for vertical reciprocation. I

Each of the plunger devices 224 includes a plunger 236 having a plunger head 238 on the lower end thereof which is reciprocable within an associated aperture 230. Disposed within the aperture 232 in flange 226 is a bushing 240 having an upper annular flange 242. The bushing 240 may be fixedly mounted within the aperture 232 by any suitable means and is adapted to slidably receive the upper end portion of the plunger 236. Flange 242 serves to limit the downward movement of the plunger as will be more fully explained hereinafter.

Mounted on the upper end of each plunger 236 is a. separable stern member 244 which may be rigidly secured. to the plunger by any suitable means. mounted between the upper end of the plunger and thestem member 244 and receives the lower end of a coil spring 248 disposed within aperture 234 in surrounding relation to the stem element 244. The upper end of spring 248 bears against a cap 250 which is threadedly engaged within the upper end of the aperture 234 and which slidably receives the upper end of the stem 244. Spring 248 thus serves to resiliently urge the plunger downwardly into engagement with the charge within the shell. A pair of cooperating stop nuts 252 are threadedly mounted on the upper end of the plunger, the lower of whichis arranged to engage flange 242 so as to limit the downward movement of the plunger.

In order to move each of the plungers into a raised position so as to permit free movement of the associated slide member 194, and the shell moved thereby, a short A collar 246 is.

on the outer end of a horizontally disposed shaft 258 extending through the central portion of each of the plungers 236. The inner end of each shaft 258 is provided with a guide roller 26% which is operable within a vertically extending slot 262 formed in the adjacent portion of the dial frame. The engagement of the guide rollers 260 within slots 262 serves to prevent the plungers from rotating about their own axes so that cam rollers 256 will at all times be disposed in a position to engage the cam track 254.

As shown in Figure 5, each plunger is maintained in its raised position by means of a latching device which will now be described. Mounted on the upper surface of the dial frame adjacent each plunger device 224 is a stud 264 having its lower end threadedly engaged within the dial frame. A latch member 266 is pivotally mounted on each stud 264 and a coil spring 263 surrounding each stud has one of its ends connected with the latch member, as by aperture 270, and its opposite end connected with the upper end of the stud as by a nut 272. Spring 263 thus resiliently urges each latch member into engagement with the upper end of the associated stem element 244. The upper end of each stern element 244 is provided with a pair of vertically spaced notches 274 and 276 within which the latch member is adapted to engage. It will be seen that when cam track 254 engages the cam roller 256 to move the plunger upwardly, the lower notch 276 will be positioned so that the latch member will be urged into engagement therewith. In this manner, the plunger head 233 is maintained in a raised position, such as shown in Figure 5, permitting the free movement of the slide member 194 and the associated shell thereunder.

Referring now to Figure 1, it will be seen that cam track 254 is positioned adjacent the outer periphery of the dial frame at a point just ahead of the point where the finished closures are transferred from the dial mechanism. As noted above, cam track 254 serves to raise the plungers and the latch members 266 maintain them in their raised position due to their engagement within the notches 276. Thus, when each plunger moves past the shell feeding dial 58, it will be disposed in a raised position permitting the associated slide member 194 to move into its outermost position so that its magnet may engage a shell S and move the same onto the associated outer seat 136. The plunger is maintained in a raised position during the movement of the shell past the charge supplying mechanism 62, while the shell remains on seat 186. After the charge been received in the shell, the charged shell is moved onto the adjacent inner seat 188 in the manner previously noted. Next, the outer end portion of the latch member 266 engages a trip roller 278 suitably mounted on the main frame 72 in fixed relation thereon in a position adjacent the outer periphery of the dial. This trip roller is arranged to engage the latch member and pivot it about the stud 264 away from stem element 24-4 and out of the notch 2'76. In this manner, the plunger is free to move downwardly into engagement with the charge within the shell under the action of spring 243. It will be understood that the engagement of the latch member 266 with trip roller 278 is momentary and that spring 263 serves to return the latch member 266 rapidly into engagement with the stern element 244. Hence, latch member 266 will enter the upper notch 274 and thus limit the amount of initial pressure which the plunger head applies to the charge by reason of spring 248.

Figure 14 illustrates the initial pressure engagement of the plunger head with the charge and in this condition the charge, during the movement of the dial, is subjected to heat by means of the heating means 64, which preferably is in the form of a gas burner. As the charge softens under the heat of the gas burner, it tends to assume an evenly distributed configuration within the shell due to the engagement of the plunger head therewith. After the charge has been heated and softened to a point sufficient to apply a final molding pressure thereto,

a second trip roller 280 is engaged by the latch member 266. As shown in Figure 1, trip roller 280 is suitably mounted on the main frame in fixed relation by an suitable means and is disposed adjacent the outer periphery of the dial frame. Engagement of the trip roller 286) will pivot the latch member out of engagement with the stem element 244 and notch 274 permitting the full force of spring 248 to urge the plunger head into engagement with the charge. This condition is illustrated in Figure 15 and it will be noted that the amount of added downward movement of the plunger is very slight. The final molding pressure is maintained for a short period after which the associated cam roller 256 engages cam track 254 which moves the plunger into its raised position. Simultaneously with the raising of the plunger, cam track 204 operates to move the slide member 194 outwardly so as to move the finished closure from seat 188 past seat 186 and deposit the same onto the chute 66. Chute 66 includes a stripper bar 232 to separate the closures from the magnets and directs the finished closures onto transverse conveyor 68 from where they are transferred to main inspection conveyor 70.

Charge supplying mechanism The charge supplying mechanism 62 comprises a hopper 2% which is suitably secured to the upper end of the shaft 119 in fixed relation thereto. The hopper 290 includes a horizontal dial plate 292 having a vertical wall 294 extending upwardly from the outer edge thereof, and a hub 2% extending upwardly from the center portion thereof. The dial plate 292 is provided with a plurality of circumferentially spaced apertures or pockets 298 which extend vertically therethrough for receiving a predetermined amount of the plastic material.

Adjacent each of the pockets 298 and spaced radially inwardly thereof is a vertical pin 300 which extends upwardly through the dial plate and through an annular ring 302 rigidly mounted, in any suitable manner, on the upper end of the hub 296. Rotatably mounted on the lower head end of each pin 300 is a lower shutter or gate valve 304, the upper surface of which engages the lower surface of the dial plate 292. An upper shutter or gate valve 306 is mounted on each pin 3% above the dial plate 292 by means of a slot and key connection 308 which permits the upper gate valve to move axially with respect to the pin. A spring 310, surrounding each pin between the upper end of the associated upper gate valve 366 and the lower end of a collar 312 suitably fixed to the upper end portion of the pin 3530, urges the lower surface of upper gate valve 306 into engagement with the upper surface of the dial plate and the upper surface of lower gate valve 304 into engagement with the lower surface of the dial plate.

As shown in Figures 7-13, the upper and lower gate valves are arranged to open and close the upper and lower ends of the charge measuring pockets 298 in timed relation so that each pocket may be filled with granular plastic material through its open upper end with its lower end closed, and discharge the granular material into a shell S through its open lower end with its upper end closed. To this end, an upper frame member 314 is suitably secured to the main frame 72 in fixed relation, and has a plate 316 extending horizontally therefrom above the hopper 2%. Plate 316 includes an aperture 318 through which a chute 320 extends so as to position the same in fixed relationship to the hopper. The chute 320 is adapted to feed granular plastic material to the hopper and the level of the plastic material in the hopper is automatically maintained by the material accumulating against the beveled open end 322 of the chute. The pressure thus created against the plastic material in the chute will prevent it from falling into the hopper. As the level of the material in the hopper drops, this pressure will be relieved and additional material will flow down the chute.

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